XRT73L03 Datasheet, PDF (57/62 Pages) Exar Corporation – 3 CHANNEL E3/DS3/STS-1 LINE INTERFCE UNIT

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PRELIMINARY
3 CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT XRT73L03
REV. P1.0.13
NOTE: If the Digital LOS Detector is disabled, then the
RLOS input pin is only asserted by the ALOS (Analog LOS
Detector).
Bit D0 - REQEN (Receive Equalization Enable -
Channel(n))
This Read/Write bit-field is used to either enable or
disable the Channel(n) internal Receive Equalizer of
the XRT73L03.
Writing a "1" to this bit-field enables the Internal
Equalizer. Writing a "0" to this bit-field disables the
Internal Equalizer.
5.2.4 Command Register CR3-(n)
The bit-format and default values for Command Reg-
ister CR3 are listed below followed by the function of
these bit-fields.
COMMAND REGISTER CR3-(N)
D4
D3
D2
D1
D0
SR/DR_(n) LOSMUT(n) RxOFF(n) RxClk(n)INV Reserved
0
1
0
0
0
Bit D4 - SR/DR_(n)(Single-Rail/Dual-Rail Data Out-
put - Channel(n))
This Read/Write bit-field is used to configure Chan-
nel(n) in the XRT73L03 to output the received data
from the Remote Terminal in a binary or Dual-Rail for-
mat.
Writing a "1" to this bit-field configures Channel(n) to
output data to the Terminal Equipment in a binary
Single-Rail format via the RPOS(n) output pin.
RNEG(n) is grounded. Writing a "0" to this bit-field
configures Channel(n) to output data to the Terminal
Equipment in a Dual-Rail format via both the
RPOS(n) and RNEG(n) output pins.
Bit D3 - LOSMUT(n) (Recovered Data MUTing dur-
ing LOS Condition - Channel(n))
This Read/Write bit-field is used to configure Chan-
nel(n) in the XRT73L03 to NOT output any recovered
data from the line while it is declaring an LOS condi-
tion.
Writing a "0" to this bit-field configures the chip to out-
put recovered data even while the XRT73L03 is de-
claring an LOS condition. Writing a "1" to this bit-field
configures the chip to NOT output the recovered data
while an LOS condition is being declared.
NOTE: In this mode, RPOS(n) and RNEG(n) is set to "0"
asynchronously.
Bit D2 - RxOFF(n) (Receive Section - Shut OFF Se-
lect)
This Read/Write bit-field is used to shut-off the Re-
ceive Section of Channel(n) in the XRT73L03. The
purpose of this feature is to permit conservation of
power consumption when this is the back-up device in
a Redundancy System.
Writing a "1" into this bit-field shuts off the Receive
Section of Channel(n). Writing a "0" into this bit-field
turns on the Receive Section of Channel(n).
Bit D1 - RxClk(n)INV (Invert RxClk(n))
This Read/Write bit-field is used to configure the Re-
ceiver of Channel(n) of the XRT73L03) to output the
recovered data on either the rising edge or the falling
edge of the RxClk(n) clock signal.
Writing a "0" to this bit-field configures the Receiver to
output the recovered data on the rising edge of the
RxClk(n) output signal. Writing a "1" to this bit-field
configures the Receiver to output the recovered data
on the falling edge of the RxClk(n) output signal.
Bit D0 - Reserved
This bit-field has no defined functionality.
Command Register CR4-(n)
The bit-format and default values for Command Reg-
ister CR4 are listed below followed by the function of
each of these bit fields.
COMMAND REGISTER CR4-(N)
D4
D3
D2
D1 D0
Reserved STS-1/DS3_ Ch(n) E3_Ch(n) LLB(n) RLB(n)
0
0
0
0
0
Bit D4 - Reserved
This bit-field has no defined functionality.
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